Tuesday, February 1, 2011

February 1, 2011 - Different Types of Heating

Today, we went over homework and took the science quiz scheduled for yesterday. The homework was to find 3 types of heating. Here are the three types:

Convection

Conduction

Radiation

Convection is the transfer of heat energy in a gas or liquid. An example of this is a hot coffee cup. Heat leaves the coffee cup as the currents of steam and air rise. Another example is that convection is responsible for making macaroni rise and fall in a pot of heated water.

Conduction is the transfer through matter from particle to particle. Conduction is most effective in solids, but it may occur in fluids. An example of conduction is a spoon in some hot soup. The spoon becomes warmer becomes warmer because the heat is conducted along

the spoon. Another example of conduction is when you touch metal. When you touch a metal spoon, it usually feels colder than you. The metal spoon is not colder though. It only feels colder because it conducts heat away from your hand.

Radiation is electromagnetic waves that transport energy directly through space. An example of radiation is sunlight. Sunlight moves directly through space to Earth, without help from any fluids or solids. Another example of radiation is a light bulb. The closer your hand gets to the light bulb the warmer it feels. The light bulb is emitting heat without any help from fluids or solids, like sunlight.

I m confused about your light bulb example. You said that radiation s when i passes through nothing and convection or conducting is when it passes through a gas. Air is a gas, so I do not see why it falls under the radiation categoryMk

And to MPIt depends on the situation. When it is in soup, the soup is hotter than the spoon. The heat is conducted up through the spoon causing it to heat up. According to JL when the spoon is in your hand, it conducts the heat energy away from your hand. Basically it attracts the heat energy whether it is warmer or cooler than the spoonMKP.S does this count as two comments